Prefabricated sheet metal truss and fastening means for two sheet metal structural members



ay 1961 H. D. THOMPSON PREFABRICATED SHEET METAL TRUSS AND FASTENINGMEANS 'FOR TWO 'ISHEET METAL STRUCTURAL MEMBERS .2 Sheets-Sheet 1 FiledNOV. 9. 1954 May2, 1961 H. D. THOMPSON 2,982,055

. PREFABRICATED "SHEET 'METAL TRUSS AND FASTENING MEANS FOR Two SHEETMETAL STRUCTURAL MEMBERS Filed Nov. 9. 1954 2 Sheets-Sheet 2 Hora/a ..flThom 0:00

INVENTOR.

U ted States Patent PREFABRICATED SHEET METAL TRUSS AND FASTEMNG MEANSFOR TWO SHEET METAL STRUCTURAL MEMBERS Harold D. Thompson, Houston,Tex., assignor, by mesne assignments, to Modular Buildings, Inc.,Houston, Tex.

This invention relates to a means for transmitting a load between twosheet metal structural members and more particularly to a prefabricatedtruss of sheet metal structural members which may be quickly and easilyassembled by unskilled labor. In one important aspect, it relates to afastening means for transmitting the longitudinal load from a top chordto the bottom chord of a prefabricated sheet metal truss.

The recent trend in home building has been toward factory prefabricationof as many elements of the home as possible to reduce costs. The rooftruss has received its share of attention, but the most that has usuallybeen done is to prefabricate and completely assemble each truss at thefactory and ship the assembled truss to location. Where the attempt hasbeen made to ship the truss sheetKmetal structural members for thecomponent elements of a roof truss. These efiiorts have beenunsuccessful largely due to the lack of a suitable joint between the topchords and the bottom chord of the truss as sheet metal screws, boltsand the like tend to tear out of the thin walls of the sheet metalmembers under the roof load.

It is an object of this invention to provide a prefabricated truss ofsheet metal structural members which may quickly and easily be assembledby unskilled labor with a minimum number of bolts, screws or the like.

Another object is to provide a prefabricated truss of sheet metalstructural members which may be nestled together for shipment in acompact bundle, and quickly and easily assembled on location to form atruss.

Another object is to provide a connection between two sheet metalstructural members in which there is a large area abutment contactthrough which the load on one member may be transmitted to the othermember.

Another object is to provide a connection between a top chord and thebottom chord of a sheet metal truss in which there is a large areaabutment contact through which the longitudinal load imposed on the topchord may be transmitted to the bottom chord of the truss.

- Another object is to provide a truss made of sheet metal members whichmay be nestled together for shipment in which a large area abutmentcontact is provided between the top chords and the bottom chord when thetruss is assembled and the abutment parts carried by the top and bottomchords do not interfere with the bottom chord nestling with the topchords when the latter are exended in a straight line.

Another object is to provide a truss of sheet metal channels in whichthe flange portions of the channels are held against buckling at theconnection between each top chord and the bottom chord. V

.Otherhbjects, features and advantages of this invention Patented May 2,1961 will appear from a perusal of the drawings, the writtenspecification and the claims.

In the drawings wherein there is shown by way of illustration oneembodiment of this invention and wherein like reference numeralsindicate like parts:

Fig. 1 is a view in side elevation of a sheet metal truss constructed inaccordance with this invention and resting upon bearing walls;

Fig. 2 is a view in side elevation of the principal components of thetruss of Fig. 1 after they have been formed but before being bent to theproper shape and assembled;

Fig. 3 is a view in cross section of the several components of the trussas shown in Fig. 2, with the components of the truss nestled togetherfor shipment;

Fig. 4 is a view in vertical cross section taken along the line 44 ofFig. 1;

Fig. 5 is an exploded isometric view on an enlarged scale of theabutment connection between the top and bottom chords;

Fig. 6 is an isometric view on a still further enlarged scale of theabutment connection between the top and bottom chords with parts brokenaway to illustrate details of the connection;

Fig. 7 is a fragmentary view in side elevation on an enlarged scale of aportion of the truss of Fig. 1, illustrating the connection between thediagonal bracing and the bottom chord, and the indentations in theflange portion of the bottom chord to secure a wood filler within thebottom chord;

Fig. 8 is a cross-sectional view through a modified form of bottomchord; and

Fig. '9 is a fragmentary side view on an enlarged scale of the truss ofFig. 1 at the peak of the truss with parts broken away to illustratedetails of construction.

The truss of this invention is preferably made up of channel-shapedstructural members formed from sheet metal, such as, for example,16-gauge steel. Three basic channel sizes are employed with the topchords formed from the larger channel size member, the diagonal bracing,and the pressure plate and clip of the connection between the top andbottom chords formed of the intermediate size channel, and the bottomchord formed of the smaller size channel. Preferably, the channel sizesare such that the smaller channel will nestle snugly within theintermediate channel and the intermediate channel will nestle snuglywithin the larger channel. This preferred sizing will permit theunassembled truss to be shipped as a compact unit, and when the truss isassembled will result in a more rigid structure. The stop and pressureclips. are secured to the bottom and top 7 chords respectively over alarge area which will transmit the expected loads, as by welding, andare arranged to have end faces in abutment to transmit the longitudinalload on the top chord to the bottom chord. This arrangement permits theconnection between the top and bottom chords of the end of the truss tobe made with a single bolt and vastly simplifies assembling the truss.

Referring now more in detail to the drawings, top chords 10 and 11 arefabricated from a length of the large size sheet metal channel. Othertypes of structural beams might be used, but a beam including a web andchannels arranged in U form, at least in the area where the pressureclip is attached to the chord, is preferred so that the top and bottomchords and their respective clips maynestle together for additionalstrength. Referring to Fig. 2, a pie-shaped wedge 12 is shown to be cutfrom the flange portions of the large size channel at its mid' eachother when the truss is assembled, as best shown in Fig. 9. This anglewill, of course, be determined by the pitch of the truss. Spaced alongthe flange portions of chords and 11 are holes 13, 14, 15, 16, 17 and18. These holes may be pre-stamped in the chords and receives boltsduring the, assembling of the truss as will more fully appearhereinafter.

Top chords 10 and 11 each carry respectively pressure clips 19 and 20which transmit the longitudinal load on the top chords to the bottomchord. These clips are identical as are the stop clips with which theycooperate and the description will be directed to clip 20 with theunderstanding that it applies as well to clip 19 and the connection atthe other end of the truss. These clips are short sections ofintermediate size channel-shaped members and are secured to therespective top chords in a partially nestled relation therewith as bywelding the lower edge of the flanges of the top chords to the outerwall of the pressure clip, which underlies the flange portion of the topchord as at 22. Inasmuch as weld 22 transmits substantially all of thelongitudinal load from the top chord to the pressure clip, the weldshould extend over an area sufiicient to transmit the expected load onthe top chord and pressure clip 20 should have a length dimensionsufiicient to permit such a weld.

The end face 21 of pressure clip 20 closest to the adjacent end of thetruss or most remote from the center of the truss provides an abutmentmember for engagement with an abutment member on stop clip 23 carried bybottom chord 24. The abutment surface 21a provided by the end faces ofthe flanges of the pressure clip 20 preferably extends in a directionrelative to the length dimensionof the top and bottom chords which willtend to draw the bottom chord more snugly into pressure clip 20. As bestshown in Fig. 6, this surface may be at a right angle to the lengthdimension of bottom chord 24 and to the length dimension of the clips.With this angle there is a slight wedge action between abutment surface21a and the complementary surface 23a of stop clip 23 when the truss isloaded, which wedge action tends to draw the bottom chord more snuglyinto pressure clip 20.

Clip 20 preferably extends in a direction relative'to the lengthdimension of the top chord which will snugly receive bottom chord 24 andprovide a large area contact therewith to hold the bottom chord againstupward movement relative to the top chord. As shown in Fig. 6, thisdirection of extension of clip 20 is preferably parallel to thedirection of bottom chord 24 when the truss is assembled and the entireweb of the pressure clip is in abutment with the web of the bottomchord.

Pressure clip 20 may be provided with laterally extending ears 25 whichprovide a ready means of securing the pressure clip to the plate 26 ofbearing walls 27 as by bolts or the like. The bottom surface of ears 25lies substantially in the same plane as the lower edge of bottom chord24 when the bottom chord is snugly received in pressure plate 20. Thus,when cars 25 are secured to plates 26, the plates together with pressureclip 20 comprise a box which completely surrounds bottom chord 24. Whenears 25 are tied to plate 26, the fastening assembly is strengthenedagainst outward buckling or spreading of the flange portions of theclips and bottom chord which might permit the clips to slide over eachother. This latter feature while a preferred embodiment is not essentialand, if desired, ears 25 may be omitted and the truss secured to hearingwalls 27 in any suitable manner.

Bottom chord 24 is provided at each of its ends with a stop clip 23which cooperates with pressure clips 20 as heretofore pointed out toprovide a fastening assembly between the top and bottom chords. Stopclip 23 is fashioned from a channel-shaped sheet metal member of thesame intermediate channel size as pressure clip 20 so that the end facesof the two clips will match when in abutment. The stop clip may besecured to bottom chord 24 in any desired manner such as by weld 28. Aspartially shown in Figs. 5 and 6, weld 28 extends along the entireoutboard end face of stop clip 23 to attach the stop clip to the bottomchord over the large area necessitated by the thin gauge steel of thebottom chord and stop part. As in the case of the pressure clip, thearea of weld 28 should be such as will transmit the expected load on thetop chord.

As best shown in Figs. 1 and 2, the stop clips 23 should be spaced alongbottom chord 24 at positions which, with chords 10 and 11 extending in asingle direction, will permit the stop clips to bev nestled within thetop chords inboard of pressure clips 19. and 20 for transport. At thesame time abutment faces 23a of the stop clips should be spaced apart asufficient distance to engage abutment faces 21a of the pressure clipswhen the chords are in their assembled positions as shown in Fig. 1. Theabutting end faces 23a of the flanges of stop clip 23 should extend atright angles to the length dimension of the clip so as to abut edges 21aof pressure clip 20 along their entire length.

A means for selectively fastening the bottom chord to the top chord isprovided to hold the truss in assembled form. This means may include ahole 29 which extends through each stop clip 23 and bottom chord 24 andis in register with hole 18 of chord 11 when the chords are in assembledposition. A bolt 30 is received in these registering holes and maintainsthe truss in assembled position. It should be pointed out that there isno substantial amount of stress transmitted by bolt 30 when the truss isloaded as the load is transmitted to bottom chord 24 through theabutment surfaces 21 and 23a.

A wood filler 31 is nestled within bottom chord 24 and extends theentire length thereof. Filler 31 is maintained in place by indentions 32in the flange portions of bottom chord 24. These indentions extend intofiller 31 and secure the filler within the bottom chord. Filler 31provides a base to which a ceiling may be nailed and additionallyprevents inward buckling of any portion of the fastening assembly. Thus,it will be seen that filler 31 cooperates with cars 25 and bolt 30 toeliminate any possibility of buckling of clips 20 or 23 and theconsequent disengagement of abutment surfaces 21 and 23a.

Referring to Fig. 8, there is shown a modified form of bottom chord 24ain which the channel-shaped chord is closed by a sheet metal flange 24bwhich extends outboard of the channel-shaped portion of the chord andprovides an anchor for splines when the ceiling is to be secured to thetruss by keepers. If desired, the ceiling may be nailed to flange 24bwith metal nails. This flange 241) will also serve to reinforce thebottom chord and prevent inward buckling of the side walls of the chord.

As best shown in Fig. 1, intermediate bracing is provided between bottomchord 24 and each of top chords 10 and 11. The bracing may comprisediagonal struts arranged in the shape of a W as illustrated. Preferably,

the diagonal bracing is formed of a section of intermediate size channel33 with the side flanges of the section of channel 33 cut and punched asshown in Fig. 2 to permit the channel member to be bent in the form of aW as shown in Fig. 1.

Bending of channel member 33 is facilitated by the removal of apie-shaped wedge 34 of material from each of the flanges of member 33 atsubstantially the mid point of the member. This permits member 33 to bebent downwardly from the apex of the pie-shaped wedge 34 to formdiagonal struts 35 and 36. The diagonal braces 35 and 36 are providedwith apertures 37 and 38 which with the diagonal braces in the positionshown in Fig. l are in register with holes 15 and 16 of top chords 10and 11, respectively. 'As best shown in Fig. 9, a

triangular fille r 39 of wood or the like is received within thechannelof members'35 and '36 andpreventsinward cut 34 and one end of member 33,spaced transverse slits 42 and 43 are made in the flange portions ofmember 33 to define ashort section 44 about which diagonal 35 anddiagonal ,36 may be bent. In other words, section 44 may be bentupwardly relative to diagonal 35 so as' to extend parallel to bottomchord 24 as best shown in Fig. l and short diagonal strut 36 may be bentupwardly relative to section 44 to form one short leg of the W truss.Section 44 is provided with an aperture 45 which with the W bracing intheposition shown in Fig. l is in register. with a hole 46 in the flangeportions of bottom chord 24 and provides a means of securing the shortsection 44 to the bottom chord with a single bolt 47. Thus, the twodiagonal struts 35 and 36 will be secured to the bottom chord with but asingle bolt. The other end of channel member 33 is provided with similartransverse slits and apertures to permit diagonal struts 48 and 36 to besecured to bottom chord 24 on the other side of the truss.

During transport between the factory and the building with which thetruss is to be used, member 33 will be a single piece extending in asingle direction as shown in Fig. 2 and will snugly nestle in thechannel member forming the top chords and will snugly receive bottomchord 24 as illustratedin Fig. 3. If desired, the W-shaped After theunassembled truss is transported to location, A

it is quickly and easily assembled with but eight bolts. After the topand bottom chords have been assembled as explained hereinabove, themember 33 is bent in the shape of a W as shown in Fig. 1 and is securedto the chords and bottom chord to complete the truss.

When the pitch of the truss is such that lower chord 24 will not clearpressure clips 19 and 20 in packaging the truss, the top chords may besevered at wedge 12 to permit nestling. The angular relationship of thepressure clips and top chords will depend upon the pitch of the trussand where it is necessary to sever the top chords to permit nestling, itwill usually be found that the lower chord can extend into the spacebetween the web of the chord and the web of the pressure clip. Thus, thetop chords may be jacked over the bottom chord until the ends of thelower chord are wedged between the top chords and pressure clips. Itwill then only be necessary to temporarily secure the ends of the topchords which terminate in wedge 12 to the lower chord to secure the"From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forth,together with other advantages which are obvious and which are inherentto the apparatus'; a 5

It will be understood that certain features and subcombinations are ofutility and may be employed without reference. to other featuresandsubcombinations. This is contemplated by and is within the scope ofthe claims. As many possible embodiments may be made of the I inventionwithout departing from the scope thereof, it

is to be understood that all matter herein set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

The invention having been described, what is claimed is:

1. A truss comprising, a top and bottom chord each formedfrom sheetmetal structural members with the top chord formed from a membercomprising a web and flange portions arranged to form a U in crosssection, said chords fastened together by an assembly comprising, aU-shaped pressure clip at least partially nestled in and attached to thetop chord over a substantial area which will transmit the expectedlongitudinal load on the top chord to the clip, said clip having anabutment face on the side of the clip closest to the end of the trussadjacent the fastening assembly, a stop clip at least partially nestledin the top chord and having an abutment face in engagement with theabutment face on the pressure clip, said stop clip attached to thebottom chord over a substantial area which will transmit the expectedlongitudinal load on the top chord from the stop clip to the bottomchord, and means releasably securing the chords to each other to holdthe truss in assembled form without transmitting a substantial portionof the load from the top to the bottom chord.

2. A truss comprising, a top and bottom chord each formed from sheetmetal structural members with the top chord formed from a membercomprising a web and flange portions arranged to form a U in crosssection, said chords fastened together by an assembly comprising,

. a U-shaped pressure clip at least partially nestled in and componentsof the truss in nestled relationship for shipping. As a furtheralternative means of shipping, it is contemplated that the top chordsmay be severed and the bottom chord formed in two pieces permitting thetruss to be made up in two packages for shipping.

From the above it will be seen that all the ends and objects of thisinvention have been accomplished. There has been provided a truss madeof sheet metal in which the principal points of load transfer betweenthe top and bottom chords are provided with abutment fasteningassemblies which transmit the load imposed upon the truss without theuse of a large number of bolts or screws as would be necessary in'theabsence of the abutment assembly. There has also been provided a trusswhich when disassembled may be packaged in a small compact bundle forshipment and which may quickly and easily be assembled on the job byunskilled labor.

attached to the top chord over a substantial area which willtransmit-the expected longitudinal load on the top chord to'the clip',said clip having an abutment face on the side of the clip closest to theend of the truss adjacent the fastening assembly, said bottom chordnestled in the pressure clip and held against upward movement relativetothe top chord by the clip, a stop clip at least partially nestled inthe top chord and having an abutment face in engagement with theabutment face on the pressure clip, said stop clip received about andattached to the bottom chord over a substantial area which will transmitthe expected longitudinal load on the top chord from the stop clip tothe bottom chord, and means releasably securing the chords to each otherto hold the truss in assembled form without transmitting a substantialportion of the load from the top to the bottom chord.

3. A truss comprising, a top and bottom chord each formed from sheetmetal structural members comprising channels sized to permit the bottomchord to nestle within the top chord, said chords fastened together byan assembly comprising, a pressure clip formed of sheet metal channel ofa cross-sectional size intermediate that of the top and bottom chords,said clip at least partially nestled in and attached to the top chordover a substantial area which will transmit the expected longitudinalload on the top chord to the clip with the clip extending parallel tothe length dimension of the bottom chord, a stop clip formed of sheetmetal channel of the same channel size as the pressure clip, said stopclip received over the bottom chord and attached thereto over asubstantial area which will transmit the expected longitudinal load onthe top chord from the stop clip to the bottom chord with an end face ofthe stop clip in abutment with the end face of the pressure clip closestto the end of the assaoss truss adjacent the fastening assembly, and,means releas ably securing the bottom chord in nestled position in thepressure, clip with the pressure clip and stop clip in end to endabutment whereby the load on the chordwill' be transmitted to the bottomchord through the abutting clips.

4. A truss comprising, a top and bottom chord each formed from sheetmetal structural members. comprising channels with the bottom chord of aslightly smaller channcl size than the top chord, said chords fastenedtogether by an assembly comprising, a pressure clip formed of sheetmetal channel of a channel size intermediate the size of the chords,said clip at least partially nestled in.

and attached to the top chord over an area which will transmit theexpected longitudinal load on the top chord to the clip, said clipextending parallel to the length dimension of the bottom chord which isnestled in the clip to. provide a large area contact between the web ofthe clip and the bottom chord to prevent upward movement of the bottomchord relative to the top chord, a stop clip formed of sheet metalchannel of the same channel size as the pressure clip, said stop clipsnugly received over the bottom chord in a position to have an end faceabut the end face of the pressure clip most remote from the top of thetruss and attached to the bottom chord over an area which will transmitthe expected longitudinal load on the top chord to the bottom chord, andmeans releasably securing the bottom chord in nestled position in thepressure clip with the pressure clip and stop clip in end to endabutment.

5. The truss of claim 4 wherein means including the securing means holdsthe flange portion of the two clips against outward buckling, and meansare provided to prevent inward buckling of the flange portions of thetwo clips.

6. A truss comprising, a top and bottom chord each formed from sheetmetal structural members comprising a web and flange portions arrangedto form a U in cross section, said chords fastened. together by anassembly comprising, a U-shaped pressure clip at least partially nestledin and attached to the top chord over a substantial area which willtransmit the expected longitudinal load on the top chord to the clip,said clip having an abutment face on the side of the clip closest to theend of the truss adjacent the fastening assembly, said bottom chordnestled in the pressure clip and held against upward movement relativeto the top chord by the clip, a U-shaped stop clip. carried by thebottom chord with the bottom chord nestled in the stop clip and the stopclip at least partially nestled in the top chord, said stop clip havingan abutment face in engagement with the abutment face on the pressureclip and attached to the bottom chord over a substantial area which willtransmit the expected longitudinal load on the top chord from the stopclip to the bottom chord, and means releasably securing the chordstoeach other to hold the truss in assembled form without transmitting anysubstantial portion of the load from the top to the bottom chord.

. 7. The truss of claim 8 wherein the pressure clip extends parallel tothe length dimension of the bottom chord to provide a large area contactwith the bottom chord holding the bottom chord against upward movementrelative to the top chord.

,8. A triangular truss comprising, two top chords of sheet metal channelconnected together at the ends thereof intermediate the ends of thetruss when the truss is assembled, bracing of sheet metal channel of asize to nestle within the top chords before the truss is assembled, abottom chord of sheet metal channel sized to nestle within the topchords and bracing before the truss is assembled, means connectmg saidbracing to said top and bottom chordswhen the truss is assembled and afastening assembly for each of the top chords and the bottom chord ofabutting clips of sheet metal channel, one of saidclips at leastpartially nestled in and carried by each top chord adjacent the ends ofthe truss and one received about and carried by the bottom chordadjacent each end outboard of and in abutment with the clips carried bythe top chords, said clips of the same channel size as the bracingwhereby with the two top chords extending along a line the bottom chordand bracing may be nestled within the top chords to form a compactpackage for shipment.

9. The truss of claim 8 wherein at least two braces are formed from asingle length of sheet metal channel and at an intermediate point alongthe channel the flange portions of the channel are cut laterally atspaced points to facilitate bending of each end of the'channel about ashort intermediate section when assembling the truss, said short sectionoverlying the bottom chord and providing a means of securing the bracesto the bottom chord when the truss is assembled.

10. A triangular truss comprising, a length of channelshaped sheet metalbent intermediate its ends to form the two top chords of the truss, abottom chord formed of a length of channel-shaped sheet metal ofslightly smaller channel size than the top chords, said bottom chordfastened to the two top chords at each end of the truss by an assemblycomprising, a pressure clip formed of sheet metal channel of a channelsize to be received over the bottom chord and to be nestled within thetop chord, said pressure clip at least partially nestled in and weldedto the top chord with the clip extending parallel to the lengthdimension of the bottom chord, a stop clip formed of sheet metal channelof the same channel size as the pressure clip, said stop clip receivedover the bottom chord and welded thereto in a position to have an endface abut the end face of the pressure clip most remote from the top ofthe truss, and means releasably securing the bottom chord in nestledposition in the pressure clips with the pressure clips and stop clips inend to end abutment whereby the load on the top chord will betransmittedto the bottom chord through the abutting clips, bracingextending between the top chords and the bottom chord formed of sheetmetal channel of the same channel size as said clips whereby beforebeing assembled they will nestle in the top chord, at least two adjacentbraces formed from a single member and bent into the desired angularrelationship when the truss is assembled, said stop clips on the bottomchord spaced inboard of the pressure clips when the top chords areextended in a straight line whereby the bottom chord will nestle in thebracing and top chords for shipment.

References Cited in the file of this patent UNITED STATES PATENTS593,185 Baird Nov. 9, 1897 958,752 Mackensen May 24, 1910 1,451,555Schenstrom Apr. 10, 1923 1,973,882 Pratt Sept. 18, 1934 2,477,163Barnett July 26, 1949 2,541,784 Shannon Feb. 13, 1951 2,642,825 McElhoneet a1. June 23, 1953 2,692,795 Lander Oct. 26, 1954 12,722,901 Johnsonet a1 Nov. 8, 1955 FOREIGN PATENTS 121,875 Great Britain 1919 241,846Switzerland Aug. 16, 1946 OTHER REFERENCES American Builder, July 1954,pp. 50 and 51.

